If it weren’t for the NSFW lyrics (there would be a lot of “melon farmer” substitution going on) I’d suggest the track “Monster” by Rafael Casal for a soundtrack (note, only up through about 4:00 when it segues to a different track; here’s just “Monster”), in part because it includes the lyrics “I’ve got an army that’s just waiting for me to unlock ’em / There will be no saving Gotham once they make it out of Arkham”…

I remember hearing years ago (as in, late 1990s) that Ostrander had been trying to shop one around, and that J. Michael Straczynski was interested.

Part of the problem was at the time that the rights were still up in the air: while Grimjack was owned by Ostrander himself, the city of Cynosure was part of First Comics, and after First Comics went bankrupt it was hard to tell who actually owned the rights. And it would be hard to tell a Grimjack story without Cynosure.

Quick check shows that Wikipedia mostly agrees with my vague memories, and the film script was supposed to happen in 1996 but Straczynski was too wrapped up in Babylon 5 at the time, despite still wanting to do it: https://en.wikipedia.org/wiki/Grimjack#Legal_history

Nobody’s managed to pick it back up since, even though the rights situation was cleared up over ten years ago now.